1. Field of the Invention
The present invention relates generally to electro-optical fire control systems, and more particularly, to a multi-spectral boresight target generator for use in such systems.
2. Description of Background Art
Modern military vehicles, such as helicopters, tanks, or fighter/interceptor planes, for example, employ electro-optical fire control systems, using multiple sensors to detect and track desired targets and delivery weapons thereto. The multiple sensors may include a visible (television) sensor, a forward looking infrared sensor, and laser rangefinder or target designator, all disposed on a single gimbal. In order to meet weapon delivery and laser designation performance goals, the boresight accuracy among the various sensors is required to be less than one pixel.
Conventional alignment systems for use with multiple sensors integrated on a single gimbal typically use multiple sources or mount the sources off-gimbal. These systems have a number of disadvantages which are manifested as poor boresight performance caused by several factors. The first is poor image quality resulting from residual stabilization noise. Another disadvantage is boresight error buildup resulting from multiple targets and optical paths used to generate the visible, laser, and infrared target beams. Very long boresight time lines, on the order of minutes, caused by slow heating of the infrared target and the processing time required to fire the laser, is an additional disadvantage of the prior art. In addition, these alignment systems are in general costly to build and align due to the reliance on precision assembly to produce an initial alignment setting, which is assumed to be maintained throughout the life of the system.
Accordingly, it is an objective of the present invention to provide an improved boresight target generator for use in an electro-optical fire control system. A further objective of the present invention is to reduce stabilization noise in boresight target generators. Still another objective of the invention is to provide a boresight target generator having reduced boresight error buildup. A further objective of the present invention is to reduce the number of optical paths utilized in boresight target generators. Yet another objective of the invention is the provision of a boresight target generator design having decreased boresight time lines. A still further objective of the present invention is the provision of cost efficient boresight target generator alignment system.